A wire E.D.M. is used by manufacturers to make precision cuts in work pieces. To provide optimal cutting results, it is necessary to secure firmly and orient each work piece being cut. Various clamping systems are used in precision machinery to releasably secure and orient a work piece.
Typically, the clamping systems include a leveling head having a clamping portion for securing a work piece and a base portion for securing the clamping device to a support surface. The clamping device is fastened directly to a machine tool support surface and the leveling head directly contacts the support surface.
A problem with these systems is that laying the leveling head directly on the machine support surface causes excessive wear to the surface. For example, placing and removing the leveling head on and from an E.D.M. table, made of soft stainless steel, often causes scratches and divots, or otherwise damages the table. Since a damaged table can lead to imprecision, even damage appearing minor can nonetheless generate the need to replace the support surface.
Another problem with the leveling head being mounted directly on the support surface of a machine tool is that a limited number of directional adjustments can be made to the device. Further, it is inconvenient to attach and remove the clamping device from the machine tool as an Allen wrench or other tool is usually required to attach a releasing lever before the device can be removed. Yet another problem is that the systems are expensive and so bulky that the machine tool does not have the capacity to accommodate a stack of clamping devices to provide additional clamping support.
What is needed, then, is a clamping fixture that includes a work piece holder that does not contact the support surface of a workstation. A fixture that is more affordable to manufacturers and that can be stacked one atop another is also needed. Further, it is desirable to have a fixture that can easily be finely adjusted, wherein the work piece holder includes clamping jaws that can be quickly interchanged. Thus, it is an object of the invention to provide an improved clamping fixture.